Swelling index

Gastric emptying is a complex process and makes in vivo performance of the drug delivery systems uncertain. Floating Bilayer drug delivery system is combined principle of bilayer tablet as well as floating mechanism. Floating drug delivery system provides advantages local delivery to specific region like stomach and proximal small intestine and it’s also shows better bioavailability and improved therapeutic activity. Floating Bilayer tablet is suitable for sequential release of two drugs in combination, separate two incompatible substances and also for sustained release tablet in which one Layer is immediate release as initial dose and second layer is maintenance dose. The purpose of this paper is to review the concept of Floating Bilayer drug delivery systems with the recent literature and current technology used in the development of Floating Bilayer drug delivery system as well as summarizes evaluation method and applications of various floating dosage forms. Key words: - Bilayer Floating drug delivery systems, Gastric residence time, Swelling index, Buoyancy